


Love(less)

by okayylmaocomputer97



Category: Gravity Falls
Genre: Angst, Angst and Fluff and Smut, F/M, Other Additional Tags to Be Added, Sibling Incest, Slow Build, pinecest - Freeform
Language: English
Status: In-Progress
Published: 2016-05-11
Updated: 2016-05-10
Packaged: 2018-06-07 17:22:32
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 4,032
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6816529
Author URL: https://archiveofourown.org/users/okayylmaocomputer97/pseuds/okayylmaocomputer97
Summary: <blockquote class="userstuff">
              <p>Mabel Pines is in love with her twin brother, Dipper Pines. This is the story of how their relationship came to be and eventually crumbled.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> I originally started this work in September 2015, but due to schoolwork and depression, I lost time and motivation to write this. I originally planned on uploading this as one long work but I was sick of waiting, so I have decided to upload it in multiple, smaller parts. This is my first Pinecest fic and I'm really enjoying writing it so far. This is the longest thing I've ever written; it's  
> my magnum opus so I'm very proud of it. Enjoy! Feedback & critique is much appreciated.

Her brother is soft and warm under her fingers. He trembles slightly; Mabel cant tell if it’s from excitement or disgust.

Mabel ignores the possibility of the last option. They’ve waited _years_ to do this. There’s no turning back now, no time to feel sinful.

Mabel chastely kisses Dipper, before bending down to wrap her lips around his cock.

* * *

 

They weren’t always sinners.

Long ago, they were brother and sister, simple like that. Mabel spent her time singing and doing arts-and-crafts. Her jocund personality easily attracted friends, who she spent lots of time with. Dipper preferred to stay home and read sci-fi books and play videogames, often making up wacky conspiracy theories.

Why exactly Mabel fell in love with her brother, she still finds inscrutable. Maybe it’s his good looks, or that rare, previous smile of his. Or maybe it was how his personality was completely opposite of hers, thus balancing her out? How he subtly reminded her to take life slowly and think? Any way, Mabel wasn’t complaining. Her brother was great, and she loved him.

_Love_ loved him.

Perhaps the first time she can recall feeling that sense of love, love not meant for a family member, was during their summer vacation in Gravity Falls, when they were both only 12.

Gideon has gotten hold of the mystery shack, then chased Dipper and Mabel in a giant robot of himself. Has had snatched Mabel away, but Dipper was quick to fight back, leaping into the robot and fighting Gideon head-on. The robot fell from the train tracks they were on, smashing into pieces upon impact with the ground. But Mabel, being the action girl she is, had managed to grab hold of Dipper during the fall and use her grappling hook to safely get them down.

It was during that moment, as the twins glided down, with Dipper in Mabel’s arms, that she felt her heart beat a little faster and her smile grow a little wider at the sight of her brother smiling and the sensation of him pressed against Mabel. Tingles ran up and down her spine.

“Told you it would come in handy,” Mabel teased.

“Mabel,” Dipper gasped when they landed. “that was amazing!”

“Not as amazing as you defeating that robot!” She replied, playfully punching him. The desire to protect her brother was stronger than ever, burning in her chest. 

“ _My brother is so cute…”_ Mabel thought as she watched him pick up his journals. She quickly apprehended herself. “He’s your brother! You can’t think of him like _that!”_ However, she was quickly distracted by the arrival of the police and Gideon. 

It wasn’t until much later, in the last week of August, during Weirdmageddon, that Mabel had those thoughts and similar sensations again.

She had been in her bubble, relaxing and letting her imagination run wild, when Dipper, Soos, and Wendy has broke in. 

At the time, Mabel was still upset over Dipper choosing to stay with Stanford, but she had never been so relieved to see her brother before. her heart ached seeing him and the others dirty and bruised, so she quickly cleaned them up, and even let them imagine whatever they wanted to be happy. They quickly did so and ran off with their fantasies.

Dipper, however, refused, irking Mabel. He stormed off, and Mabel sighed. 

“Hey, don’t worry! You can hang out with _me!_ ” Dippy Fresh, a pathetic clone of her brother, offered. 

“No, thank you,” Mabel sighed, shaking her head and looking down at the floor. She wanted _Dipper_ , not Dippy. But why did she want him so badly?

“B _ecause I love him,_ ’ Mabel thought. She blinked. _“He’s my brother, after all!”_ Mabel quickly covered up the previous thought, but part of her knew deep down that she didn’t mean in a platonic, sibling type way. She suppressed it though, and instead focused on going outside to play with her friends. 

And then things began to escalate. Between the ages of 13 and 15, a series of… _peculiar_ events occurred between the Mystery Twins.

The first was when they were 13 years old.

Family Life Education was a mandatory part of the 8th grade curriculum. With FLE came sex-ed, and of course, masturbation was brought up.

Mabel jokes about it with her friends, but she couldn’t help but grow curious, so she tried it herself and enjoyed it. She often did it once or twice a week, to the thought of some cute boy or girl in her class. She never felt gross; for someone in the midst of puberty with an emerging sexuality, this was all normal.

She knew Dipper did it as well, because sometimes, late at night when she was reading or texting her friends, if she listened closely enough, she’d hear soft pants and moans coming from next door, where Dipper slept. Mabel thought it was super gross and ignored it with a blushing face.

Except one night, when Mabel was awake reading a silly teen-romance novel, she heard a particularly loud pant and grunt, followed by a breathy moan.

“M-Mabel…”

Mabel’s jaw dropped. Did she really just hear that? Her brother, moaning her name as he came? She didn’t know how to feel. Disgusted that it was her brother, or flattered that someone found her attractive enough to be the object of fantasy?

Mabel slammed her book shut and buried her face in her pillow. She wanted to scream, but then Dipper and possibly her parents would hear. Instead, she lay there, mentally freaking out.

_“OHMYGODOHMYGODOHMYOD”_

This went on for a while, before Mabel finally calmed herself down and forced herself to believe it was all a mishearing.

“Besides,” she whispered to herself. “Who’s to say he was even masturbating?” But what else could it have been, then? Mabel ignored the thought. For the rest of the weekend, Mabel couldn’t look Dipper in the eye.

And yet, the next week, Mabel found herself thinking of Dipper and softly moaning his name as she came.

A year later, at the age of 14, the family held a pool party to celebrate the 4th of July. Lots of family members were there; grandparents, aunts, uncles, even a few cousins from New Jersey came over.

Everyone was having fun enjoying the barbecue and swimming in the large pool.

Mabel loved swimming, so she wore her favorite white bikini. Her breasts had grown quite a lot, and she now took the time to shave her body. She had also gotten a haircut. She donated her locks and now had a cute shoulder-length bob cut.

She had been treading water while talking with one of her cousins from New Jersey. However, her legs had gotten a bit tired so she politely excused herself and went to the snack table.

As she was deciding what to drink, Dipper suddenly appeared next to her, grabbing a soda.

“Hey, Dipper!” Mabel greeted her brother with a wide smile.

“Hi,” He replied nonchalantly, cracking open the can. Dipper wore nothing but a navy blue pair of swim trunks.

Mabel hadn’t seen her brother since guests started arriving a few hours ago, before they changed into their swimsuits. Mabel was busy showing guests around the house and Dipper had been preparing the snack table. 

Mabel couldn’t help but stare a little at his brother. He had some chest hair now, and he still maintained that cute, scrawny body-type. Mabel couldn’t help but find him very attractive.

She caught herself in the act, and quickly pried her eyes away from his body and back to his face.

“Soooo….” Mabel said, nervously twirling a lock of hair around her finger, hoping Dipper hadn’t caught her staring. “what’ve you been up to?”

“Just talking to Aunt Beth about school and Boy Scouts,” Dipper shrugged, before taking a long sip of hid soda. 

“Hey, I was just talking to Sam, one of our cousins from New Jersey. He does Boy Scouts, too! Why don’t you talk to him and become friends?” Mabel said excitedly, her eyes lighting up.

“I-I don’t know-” Dipper stammered. He always got nervous at the thought of social interactions. 

“Hey, wait a minute,” Mabel said interrupted, squinted at him. “your hair is dry…you haven’t been in the water at all, have you?”

“W-well, no…”

“C’mon, Dipper! This is a _pool_ party! Let’s swim together, if you’re afraid!” Mabel grabbed her brother’s hand before he could say anything, yanking him harshly over to the pool, causing him to spill his drink on the patio.

“Ouch! Mabel, be careful!” Dipper hissed as his sister excitedly splashed into the pool. 

“Come on, the water’s great!” Mabel motioned with her hands for Dipper to come in.

He hesitated, before suddenly grinning and canon-balling into the pool. Mabel shrieked and giggled in delight as she was splashed with water. Dipper’s head popped up, laughing and grabbing onto the edge of the wall for support. Mabel felt her heart give a little skip and a small burst of happiness tingled in her head at the sight of her brother so happy.

“So…what do you want to do?” Dipper asked, tilting his head.

“Hmm…” Mabel hummed loudly, tapping her chin and looking up into the corner for dramatic effect. “How about…” she clicked her tongue. “a hold-your-breath competition?” 

“Alright, but you know I always win those,” Dipper teased, gently elbowing his sister. She rolled her eyes.

“Well, maybe _I’ll_ win this time!” She challenged with a grin. Dipper simply shrugged.

“Alright,” Mabel pushed her bangs to the side. “three, two, one, go!” The twins both took a big gulp of air before simultaneously plunging their bodies underwater. 

Mabel kept her eyes sealed shut. It wasn’t that she couldn’t open them in water, but rather Dipper would always make funny faces to try to make her laugh.

“ _One, two, three, four, five…”_ she counted in her head. Her current record was 32 seconds, while Dipper’s was an impressive minute and 18 seconds.

The water was so cool and relaxing. It felt so nice, enveloping her entire body. She could hear her heartbeat and the blood rushing in her ears.

“ _Seventeen, eighteen, nineteen…”_

She could feel Dipper staring at her, feel his gaze burning into her.

“T _wenty-three, twenty-four, twenty-five…”_

She could feel her chest grow painfully tight. Mabel clenched her fists and squirmed around in pain, unknowingly pushing her chest out.

_“Thirty, thirty-one, thirty-two…”_

She tightly clenched her jaw as she felt Dipper’s gaze trail down her neck to her chest.

_“Thirty-seven, thirty-eight, thirty-nine…”_

Her chest burned from the pain.

_“Forty-two, forty-three, forty-four…”_

Or was it Dipper’s gaze that was causing it to burn?

_“Forty-seven, forty-eight…”_

Mabel’s head spun and her chest felt like it was going to explode. She propelled herself up to the surface, gasping loudly and pushing her hair out of her face. The fresh, cool air soothed her burning lungs.

Dipper popped back up a few seconds later, calmly sucking in air.

“I won!” He announced. Mabel smiled, still catching her breath.

“Heh, yeah, but that’s a new record for me! Forty-eight seconds!”

“Congrats,” Dipper congratulated her with a pat on her shoulder. Mabel suddenly felt an intense stinging pain on the knuckles of her right hand.

“Ouch!” she exclaimed, pulling them up from under the water. Her knuckles were red and bruised, scratched up with a few tiny dots of blood.

“I must’ve scraped them on the wall when I pushed myself up,” Mabel thought out-loud.

“Oh no. They look pretty hurt,” Dipper said with concern in his voice. He gently held Mabel’s hand to lift it up and get a better look. 

“Mom keeps the bandaids in the bathroom inside,” Mabel said, annoyed that she would have to leave the party to fix a stupid injury she could have easily prevented. “But I read online that, like, the chlorine in pools sterilizes the cuts?” Mabel hoped the nerdy fact, whether it was true or not, would cheer Dipper up and get that worried look off his face.

Dipper said nothing for a moment. He stared intently at Mabel’s hand.

“D-Does it still hurt?” He asked softly.

“Yeah, kind of,” Mabel mumbled. “and I know the anti-bacterial cream will make it sting even more…” she cringed a little. She hated pain.

Dipper pursed his lips. Mabel noticed he was beginning to sweat a little.

“Dipper?” She whispered, raising her eyebrows in concern. Was he okay?

“M-Maybe this will help,” he said in a quick, almost scared voice.

With that, he pushed his lips out and pressed them against the injured knuckles in the same fashion a mother would kiss a child’s injury to make it feel better.

Mabel stared wide-eyed at her brother. Her mind when blank. She felt her heartbeat speed up and her cheeks grow warm. Dipper’s eyes were closed tightly.

Mabel’s eyes darting around, hoping nobody would see them doing this. She was relieved when they didn’t, but she still had no idea how to feel. Her brain finally processed the entire situation, and she realized her not doing anything was probably exacerbating it. She gently puled her hand away from Dipper.

The two said nothing, just staring at each other with wide eyes for a few long seconds. Both were blushing madly.

Finally, Mabel cleared her throat and spoke.

“I’m…gonna go get a bandaid,” she said awkwardly. Dipper blinked, then nodded.

Mabel quickly hauled herself out of the pool. Yeah, that was enough swimming for today. She scurried inside the house and to the bathroom, grabbing the pack of bandaids from the medicine cabinet. 

As she applied one, she couldn’t help thinking about how gently Dipper held her hand, and how nice his cool lips felt against her bruised skin.

She regretted pulling her hand away.


	2. Chapter 2

Mabel fell in love with Dipper when she was 15.

It was early spring and the two were seated together on the school bus, talking about their day. Mabel had a chemistry test, Dipper was starting a new unit in his trigonometry class…others would find the discussion boring, but the twins enjoyed it. They didn’t have any classes together and were often gone for extracurricular activities, so they took any opportunity they got to hang out. Exchanging information on classes was their way of keeping up with each other and knowing the other was okay.

As they talked, Mabel couldn’t help but note how attractive her brother was. His cute, wavy brown hair, soft nose, deep brown eyes, high intellect…she loved it all. Her brain wandered down memory lain, reminiscing on their adventures on Gravity Falls and how close they became after that. Mabel figured if it wasn’t for that trip, they’d only be half as close as they are now. Mabel dreaded the thought.

Dipper said something, but Mabel was so deep in thought she didn’t hear it. It must’ve been funny though, because he started laughing.

He closed his eyes and gave a toothy smile, revealing his perfect white teeth. His nose scrunched up a little and he was positioned next to the window in a way that made the light hit him at a _perfect_ angle that made him look like he was glowing. Bubbly giggled escaped his and his shoulders bounced softly.

It was in that moment that Mabel fell in love. 

Her brother was so cute, so attractive, so smart and so _perfect_ that she felt her heart palpitate and an overwhelming sense of joy and desire to protect him crashed down upon her like a tidal wave. Her head spun slightly at the sudden surge of emotions.

Dipper stopped laughing and looked at her. “…Yeah?” He asked, seeking confirmation of whatever joke he told.

“Yeah,” Mabel sighed, maybe a little too dreamily because Dipper raised his eyebrows. How she wished to wrap her arms around him and hold him. But she controlled herself, and instead twiddled her thumbs nervously. Her heart was still pounding and she felt shy and embarrassed and _so small_ next to her crush, her brother.

For the rest of the school year, nothing much happens. The only big thing was Mabel finally getting her braces removed. In August, their parents decided to take them on a camping trip to celebrate their birthdays.

After a long drive, they finally reached the park and drove up to the camping reserve. After setting up tents, their parents sent the twins to fetch some firewood.

“Isn’t this beautiful, Dipper?” Mabel asked with awe as she wondered at the giant, looming trees. 

“It reminds me of Gravity Falls,” he replied with a soft smile. Mabel smiled as she remembered their vacation there.

“That was such an amazing summer,” she said, bending down to pick up a thick stick. “Everything about it was awesome.”

“The most awesome part for me was going on adventures with you,” Dipper replied, picking up a twig. Mabel giggled and blushed softly.

“That part’s my favorite, too,” she said softly. Her infatuation with her brother was still strong as ever, with no sign of going away soon.

“I’m glad we took that trip,” Mabel commented. “it brought us closer.”

“Yeah,” Dipper said softly. “we were pretty…awkward together before. We were always off doing our own separate things.” A sad silence briefly fell across the two. 

“Hey, remember Weirdmageddon?” Mabel said suddenly, trying to lighten the mood.

“How could I not? It was terrifying,” Dipper replied in a low voice. Mabel bit her lip nervously.

“Remember my crazy bubble, though?” She continued.

“Oh yeah. The colors were so bright, they hurt my eyes!”

Mabel laughed. “Sorry about that…it _was_ pretty bad.”

“Remember that stupid clone of me you made?” What did you call him again?” Dipper asked.

“Dippy Fresh,” Mabel replied with a snort. “Man, that was so cringe of me!” 

“I can’t believe you could replace me like that, with such a fake person,” Dipper says lightly. But Mabel can hear the hurt in his voice and her heart aches.

“I could never completely replace you, though,” Mabel murmurs, walking up to her brother and hugging him. “because I love you.”

There was sudden silence. Dipper froze up underneath her.

Mabel suddenly let go, a faint blush spreading across her cheeks.

“W-well, I mean-“

“I love you, too.” Dipper replied softly. He dropped his small collection of sticks and turned to face her directly. The silence came back, as they looked deep into each other’s eyes. 

Slowly and cautiously, Dipper wrapped his hand around Mabel’s and their fingers intertwined. Mabel’s heart began to pound, and Dipper’s hand felt slightly sweaty.

“Have you ever been in love?” Mabel asked softly, finally breaking the silence after several long minutes.

“Yes,” Dipper replied, eyes nervously glancing aside. She knows he’s talking about Wendy. “Have you?” His voice grew a little shaky.

“No,” Mabel lies bluntly, avoiding his gaze to look down at her feet. 

“R-really?” He’s so surprised her stammers. “But…all the boys you’ve dated..ever since we were 12 in Gravity Falls-“

“That was never love,” Mabel replied, shaking her head. “They were nice and I liked them, but none made my heart pound or my cheeks blush.” And she wished she never said that but at the same time she _doesn’t_ and her hand is clutching Dipper’s now and she slowly took a deep breath. She feels Dipper shake ever so slightly. 

“Has…anyone ever done that to you?” His voice is a whisper. It suddenly becomes so _quiet_. Mabel said nothing. She slowly lifted her eyes and met Dipper’s and they’re slowly getting closer and closer and Mabel couldn’t help but close her eyes and push her lips out and say yes in abreathy whisper before feeling her brother’s lips against her own. They’re rough and chapped while hers were soft and slathered in chapstick and for a minute, Mabel mused that some of it would rub of on Dipper and soothe his cracked lips. She gently molded her lips against Dipper’s; they fit perfectly. They _are_ twins after all, and share almost all the same genetics.

They stayed like that for a few seconds, lips and hands interlocked as the world seemed to melt away. Dipper pushed his lips against hers, moaning softly before suddenly jerking back, ripping his hand out of her grip. His eyes were wide with a mixture of horror and…something else that Mabel can’t tell.

“M-M-Mabel, I-“ He sputtered out, unable to form a sentence.

“Dipper…” Mabel breathed. She’s screaming in her head - just one long, continuous scream because this is _wrong_ , what they just did was _wrong._ Sisters shouldn’t kiss their brothers like that. But at the same time, she wishes they had kissed for just a little bit longer…

Dipper snatches up his stick collection and rushes past her, spitting out an “I’m sorry.”

Mabel watched him go, guilt and sadness and _lust_ all building up in her chest and confusing her. After a while, Mabel slowly trudged back to their tents.

For the rest of the day, and the trip, they didn’t look each other in the eye. Hell, they tried not to even look at each other at all. Their parent’s didn’t seem to notice this odd behavior, or maybe they didn’t care, writing it off as another sibling quarrel. 

The night before they returned home was their birthday. They held a nice barbecue with hotdogs and hamburgers and great presents. Mabel got some new shirts, makeup, and drawing pencils while Dipper got some video games, clothes, and science books. After cake, they cleaned up and went off to bed. 

As Mabel lay in her tent, snuggled inside her sleeping back,memories of the kiss flooded into her mind. It had been the only thing in there since it happened, and as much fun as fishing and hiking were, they just couldn’t distract her enough. Her brother was sleeping right next to her and she heard him snoring softly.

“ _I love you_ ,” She thought. She idly traced her fingers over her lips, thinking about how gently Dipper held her had and how good his rough, _hot_ lips felt against hers. Her fingers trailed down to between her legs, and she licked her lips, aching to feel Dipper’s again. Aching to have him press against her and tell her how much he loves her. She pretended her hands were his, and within a few quick minutes she came with a softly gasp and moan.

She knew this was wrong. Incest is wrong, and she should feel disgusted at having done what she just did. But she doesn’t, and maybe that’s what makes her cry herself to sleep that night. 

The first thing Mabel did when she got home was start her laundry. She had packed her favorite outfits and gotten a fear amount of dirt and sweat on them. She hauled her basket into the small laundry room and was surprised to see Dipper there, unloading his from the dryer.

Mabel avoided his gaze and said nothing as she dumped her clothes into the washing machine. As she was pouring in the detergent, Dipper spoke.

“I’m sorry. Let’s just…forget that never happened.” He let out a long sigh. 

“No, no,” Mabel said quickly and almost desperately. She had spent the past four days saying nothing to her brother. It was nice to talk to him again. “Don’t apologize.”

Dipper raised his eyebrows, but said nothing. 

“Um,” Mabel continued nervously. “do you, um…really love me like that?” She looked at him with a gaze that screamed “I love you. I’m _in_ love with you.” His cheeks were a light pink and he looked extremely flustered. He said nothing.

Mabel put the detergent bottle down and swiftly walked over to him. She pressed her lips against his cheeks, and giggled softly when she felt them grow hotter.

She then whispered in his ear, “If you ever wanna, umm…” _How do I say this without sounding lewd?_ “Chill? With me. I’m fine with that. I love you.” She quickly jumped back and started the machine before darting out of the room, feeling her brother’s gaze on her back the whole time.


End file.
